This is the first of a set of two papers dealing with the relationship between the shape of the maxillary central incisor and the inverted form of the face.The central incisor is a tooth that dominates the anterior region in terms of shape, size and location. This makes it the key to the success of any aesthetic rehabilitation. In addition, it is the only tooth to completely face the smile, which reinforces the impression of dominance. (M.Crétôt, 2015 and Etienne et al., 2007) James Leon William in 1914 advanced a theory, in which he assumes that there is a harmony between the shape of the face and that of the inverted upper central incisor. (Crétôt, 2015) Leon Williams had classified the central incisors into 3 main forms: "Ovoid", "square / rectangular", "triangular" This theory remains, today, the most accepted in the field of choice of prosthetic teeth as well as in smile design software (L. Ibrahimagi and V. Jerolimov, 2001) In this work we aim to treat the subject as follows: - At first we will briefly discuss the fundamental reminders including the anatomy of the central incisor, the harmony of the face (the golden ratio), and the theory of Leon williams. - A second chapter will concern our literature review on the correlation between the shape of the face and that of the upper central incisor. - A third chapter will concern our report on the correlation on a small sample in order to illustrate to compare and discuss our observations with those of the literature.
